Multidirectional sensor

ABSTRACT

A cylindrical seismic mass includes three equally circumferentially spaced conical depressions in its lower end wall which receive and seat a first set of balls seating in like mating depressions in a plate supported on the lower wall of a cylindrical housing. The upper end wall of the mass contains three equally circumferentially spaced conical depressions which seat a second set of balls also seating in an overlying first plate having like depressions mating with those of the mass. An overcenter disc spring supports the plate in engaged position with the second set of balls to in turn hold the mass in engagement with the first set of balls and locate the mass against movement laterally of the lower wall of the housing. An operator plate is supported adjacent the first plate by a disc spring in spaced relationship to a primer. When the mass receives an acceleration pulse of predetermined amplitude and time, it shifts generally parallel to the lower wall of the housing and the camming action of the first set of balls moves the mass axially or raises the mass. This movement of the mass and the camming action of the second set of balls axially shifts the first plate so that the disc spring thereof moves overcenter. The first plate then engages the operator plate to shift the operator plate axially so that the operator disc spring moves overcenter and the operator plate engages the primer. A modification includes a second plate supported by an overcenter disc spring between the first plate and operator plate.

Prachar [54] MULTIDIRECTIONAL SENSOR [72] Inventor: Otakar P. Prachar,Santa Barbara,

Calif.

[73] Assignee: General Motors Corporation,

Detroit, Mich.

[22] Filed: Sept. 8, 1970 [21] Appl. No.: 70,319

[52] U.S. Cl. 73/514, 200/61.45 R [51] Int. Cl. ..G01p 15/02 [58] Fieldof Search ..73/492, 514, 515; 116/114;

200/6l.45, 61.53 [56] References Cited UNITED STATES PATENTS 3,263,5048/1966 Parkinson et al. ..73/515 3,081,640 3/1963 Chatillon ..74/1102,671,832 3/1954 l-lansard et al ..200/6l.53 3,227,834 1/1966 Keese..73/514 3,267,739 8/1966 Epps et al ..200/61 .53 2,766,345 10/1956'Crites ..200/61.45 3 ,407 ,667 10/ 1 968 Doeringfeld ..200/61 .453,488,462 l/1970 Gignotto. ..200/61.45

Primary ExaminerJames J. Gill Assistant ExaminerHerbert GoldsteinAttorney-W. E. Finken and Herbert Furman "lull [4 1 Nov. 21, 1972 [5 7]ABSTRACT A cylindrical Seismic mass includes three equallycircumferentially spaced conical depressions in its lower end wall whichreceive and seat a first set of balls seating in like mating depressionsin a plate supported on the lower wall of a cylindrical housing. Theupper end wall of the mass contains three equally circumferentiallyspaced conical depressions which seat a second set of ba1ls also seatingin an overlying first plate having like depressions mating with those ofthe mass. An overcenter disc spring supports the plate in engagedposition with the second set of balls to in turn hold the mass inengagement with the first set of balls and locate the mass againstmovement laterally of the lower wall of the housing. An operator plateis supported adjacent the first plate by a disc spring in spacedrelationship to a primer. When the mass receives an acceleration pulseof predetermined amplitude and. time, it shifts generally parallel tothe lower wall of the housing and the camming action of the first set ofballs moves the mass axially or raises plate to shift the operator plateaxially so that the operator disc spring moves overcenter and theoperator plate engages the primer. A modification includes a secondplate supported by an overcenter disc spring between the first plate andoperator plate.

3 Claims, 3 Drawing Figures 8 &

III

PATENTED nuv 2 1 ma I 0 NF-;

IIII

DQL 18 ATTORNEY MULTIDIRECTIONAL SENSOR This invention relates tomultidirectional sensors and more particularly to an omnidirectionalsensor having an operator movable from normal to actuated position by amechanical amplifying means actuated by a seismic mass.

One feature of this invention is that the operator is movable betweennormal and actuated positions along a predetermined axis and themechanical amplifying means is energized by the seismic mass when themass is subjected to an acceleration pulse of predetermined amplitudeand time so as to move laterally of the direction of movement of theoperator. Another feature of this invention is that the mass shifts inthe same direction of movement as the operator upon movement thereoflaterally of this direction so as to energize the mechanical amplifyingmeans and move the operator to actuate position. A further feature ofthis invention is that multiple stage mechanical amplifying means areinterposed between the operator and the seismic mass.

Yet another feature of this invention is that the seismic mass isnormally located against movement laterally of the direction of movementof the operator as well as being shifted in this same direction uponmovement of the mass by means of mating like depressions in the mass andin a support for the mass which receive balls. Yet a further feature ofthis invention is that the mechanical amplifying means includes anovercenter type disc spring supporting the operator and an intermediatemember supported by an overcenter type disc spring and operativelyconnected to the mass, the latter spring seating the balls within themass depressions and in the like depressions in the support. Stillanother feature of this invention is that the member is operativelyconnected to the mass by balls seating in mating like depressions in themember and mass.

These and other features of the sensor of this invention will be readilyapparent from the following specification and drawings wherein:

FIG. 1 is a view of a sensor according to one embodiment of thisinvention, with the sensor being shown in normal or unactuated position;

FIG. 2 is a view similar to FIG. 1 showing the sensor in actuatedposition; and

FIG. 3 is a view similar to FIG. 1 showing another embodiment of theinvention.

Referring now to FIGS. 1 and 2 of the drawings, a sensor according toone embodiment of this invention includes a circular base plate 12having a cylindrical wall 14 extending normal thereto. Plate 12 includesa flange 16 which may be apertured at any one or more places 18 toprovide for mounting of the sensor on any suitable support such as avehicle body.

A generally frusto-conically shaped disc spring 20 has its innerperipheral edge received within a groove in the peripheral wall of acircular plate 22. The outer peripheral edge of spring 20 seats on aradially tapered axially facing shoulder 24 of wall 10. A cylindricalspacer 26 seats on the outer edge portion of disc spring 20, and theouter peripheral edge of a second disc spring 28 seats on the spacer 26.The inner peripheral edge of spring28 is received within a groove in theperipheral wall of a cylindrical operator 30 which includes a centralfiring pin 32. A generally frusto-conically shaped cover member 34 hasits outer peripheral edge seating on the outer peripheral edge portionof spring 28. The upper edge portion 36 of wall 14 is flanged or stakedover the cover plate to thereby retainthe cover plate 34, the discsprings 20 and 28 and spacer 26 in place against any bodily movementrelative to wall 14 as shown in FIG. 1. An externally threaded bushing38 is received within an internally threaded central boss 40 of plate 34and supports a percussion primer or detonator 42.

The lower end wall of a generally cylindrical seismic mass 44 includesthree equally circumferentially spaced conical depressions 46. Eachdepression seats a ball 48 which in turn seats within like shaped andspaced depressions 50 in the base plate 12. The upper end wall of themass 44 likewise includes three equally circumferentially spaceddepressions 52 each of which seats a respective ball 54. The balls 54also seat within like shaped mating depressions 56 in the lower wall ofY the plate 22. The normal free position of spring 20 is at a slightlylesser conical angle than shown in FIG. 1 so that spring 20 is slightlyovercenter. This causes plate 22 to seat the balls 54 in engagement withthe mating pairs of respective depressions 52 and 56 and in turn seatballs 48 in engagement with their mating pairs of depressions 46 and 50.Thus, the mass 44 is normally held against movement axially or radiallyof wall 14 unless an acceleration pulse of predetermined amplitude andtime is received.

When such a pulse is received, the mass 44 will shift laterally orradially of wall 14 from its FIG. 1 position to its FIG. 2 position. Asthe mass shifts radially of the wall 14, it will also shift axially ofthe operator 30 or generally normal to the wall 12 due to the cammingaction of the balls 48 or movement of these balls outwardly of theirrespective depressions 50. Likewise balls 54 will move radiallyoutwardly of depressions 52 to cam plate 22 axially of the mass. Theaxial movement of the mass and the action of balls 54 will move plate 22through a sufficient axial distance so that spring 20 will moveovercenter from its FIG. 1 position to its FIG. 2 position. Plate 22will then engage the operator 30 and move the operator axially until itsdisc spring 28 moves overcenter and the operator then moves to itsactuated position in engagement with the detonator 42 as shown in FIG. 2to fire the detonator.

The spring 20 thus functions as both a threshold spring for the mass 44and a mechanical amplifying spring for the plate 22, while spring 28functions only as a mechanical amplifying spring.

FIG. 3 shows a modification which includes an additional plate 58interposed between the operator 30 and the plate 22 and supported by arespective disc spring 60 which seats on the spacer 26. An additionalspacer 62 is interposed between the outer peripheral edge portion of thedisc spring 60 and the spring 28 of operator 38. This modification thusincludes additional mechanical amplifying means. It is believed thatoperation of this modification is apparent without any furtherdescription.

The sensor 10 of this invention is particularly intended for use with anair cushion restraint system for a vehicle body. Generally such a systemcan include a diaphragm sealed pressure vessel which communicates withan inflatable cushion in the event of vehicle impact to inflate thecushion. The primer or detonator 42 may either directly or indirectlyrupture the diaphragm of such a pressure vessel when the vehicle impactsubjects the mass 44 to an acceleration pulse of required values tothereby inflate the cushion.

Thus, this invention provides an improved omnidirectional sensor.

lclaim:

1. A multidirectional sensor comprising, in combination, a planarsupport having a plurality of spaced depressions therein openinglaterally of the support, an operator, mechanical amplifying meansmounting the operator on the support for linear movement laterally ofthe support between normal and actuated positions, the amplifying meansincluding an actuating planar member having a plurality of spaceddepressions therein opening to the support, a seismic mass having aplurality of first depressions, each opening to and paired with one ofthe support depressions, and a plurality of second depressions, eachopening to and paired with one of the planar member depressions, a ballreceived in each pair of depressions to locate the seismic mass betweenthe support and the actuating member of the mechanical amplifying meansand normally hold the seismic mass against movement, an accelerationpulse of predetermined amplitude and time applied to the seismic massmoving the seismic mass relative to the support, the balls in the pairsof depressions between the mass and the support camming the masslaterally of the support as the mass moves relative thereto, the ballsin the pairs of depressions between the mass and the actuating membercamming the actuating member relative to the mass as the mass is beingcammed normal to the support to thereby actuate the v mechanicalamplifying means to move the operator laterally of the support from itsnormal position to its actuated position.

2, A multidirectional sensor comprising, in combination, a supporthaving a plurality of generally conical depressions therein, a linearlymovable operator, first mechanical amplifying means mounting theoperator on the support for linear movement between normal and actuatedpositions, a seismic mass having a plurality of generally conicaldepressions in one side thereof opening to the support depressions andpaired therewith, a member located intermediate an opposite side of theseismic mass and the operator and including a plurality of generallyconical depressions opening to like depressions in said opposite side ofthe seismic mass and paired therewith, a ball received in each pair ofdepressions to mount the seismic mass between the member and thesupport, second mechanical amplifying means mounting the member andacting to hold the balls in the conical depressions to hold the seismicmass stationary relative to the support, the seismic mass being movedlaterally of the direction of movement of the operator when subjected toan acceleration pulse of predetermined amplitude and time, said lateralmovement of the seismic mass causing movement of the seismic mass andthe member normally of the support by camming action of the balls in theconical depressions to activate the first and second mechanicalamplifying means and move the operator linearly to actuated position.

3. A multidirectional sensor comprising, in combination, a supporthaving a plurality of generally conical depressions therein, a linearlymovab e operator, first overcenter type disc spring means mounting theoperator on the support for linear movement between normal and actuatedpositions, a seismic mass having a plurality of generally conicaldepressions in one side thereof opening to the support depressions andpaired therewith, a planar member located intermediate the other end ofthe seismic mass and the operator and including a plurality of generallyconical depressions opening to like depressions in the other end of theseismic mass and paired therewith, a ball received in each pair ofdepressions to mount the seismic mass between the planar member and thesupport, second overcenter type disc spring means mounting the member inspaced relation from the operator and acting to hold the balls in theconical depressions to hold the seismic mass stationary relative tosupport, the seismic mass being moved laterally of the direction ofmovement of the operator when subjected to an acceleration pulse ofpredetermined amplitude and time, the balls in the depressions cammingthe seismic mass normally relative the support and the planar membernormally of the seismic mass and into engagement of the operator andcausing the first and second overcenter type disc spring means to moveovercenter and thereby the operator to actuated position.

1. A multidirectional sensor comprising, in combination, a planarsupport having a plurality of spaced depressions therein openinglaterally of the support, an operator, mechanical amplifying meansmounting the operator on the support for linear movement laterally ofthe support between normal and actuated positions, the amplifying meansincluding an actuating planar member having a plurality of spaceddepressions therein opening to the support, a seismic mass having aplurality of first depressions, each opening to and paired with one ofthe support depressions, and a plurality of second depressions, eachopening to and paired with one of the planar member depressions, a ballreceived in each pair of depressions to locate the seismic mass betweenthe support and the actuating member of the mechanical amplifying meansand normally hold the seismic mass against movement, an accelerationpulse of predetermined amplitude and time applied to the seismic massmoving the seismic mass relative to the support, the balls in the pairsof depressions between the mass and the support camming the masslaterally of the support as the mass moves relative thereto, the ballsin the pairs of depressions between the mass and the actuating membercamming the actuating member relative to the mass as the mass is beingcammed normal to the support to thereby actuate the mechanicalamplifying means to move the operator laterally of the support from itsnormal position to its actuated position.
 1. A multidirectional sensorcomprising, in combination, a planar support having a plurality ofspaced depressions therein opening laterally of the support, anoperator, mechanical amplifying means mounting the operator on thesupport for linear movement laterally of the support between normal andactuated positions, the amplifying means including an actuating planarmember having a plurality of spaced depressions therein opening to thesupport, a seismic mass having a plurality of first depressions, eachopening to and paired with one of the support depressions, and aplurality of second depressions, each opening to and paired with one ofthe planar member depressions, a ball received in each pair ofdepressions to locate the seismic mass between the support and theactuating member of the mechanical amplifying means and normally holdthe seismic mass against movement, an acceleration pulse ofpredetermined amplitude and time applied to the seismic mass moving theseismic mass relative to the support, the balls in the pairs ofdepressions between the mass and the support camming the mass laterallyof the support as the mass moves relative thereto, the balls in thepairs of depressions between the mass and the actuating member cammingthe actuating member relative to the mass as the mass is being cammednormal to the support to thereby actuate the mechanical amplifying meansto move the operator laterally of the support from its normal positionto its actuated position.
 2. A multidirectional sensor comprising, incombination, a support having a plurality of generally conicaldepressions therein, a linearly movable operator, first mechanicalamplifying means mounting the operator on the support for linearmovement between normal and actuated positions, a seismic mass having aplurality of generally conical depressions in one side thereof openingto the support depressions and paired therewith, a member locatedintermediate an opposite side of the seismic mass and the operator andincluding a plurality of generally conical depressions opening to likedepressions in said opposite side of the seismic mass and pairedtherewith, a ball received in each pair of depressions to mount theseismic mass between the member and the support, second mechanicalamplifying means mounting the member and acting to hold the balls in theconical depressions to hold the seismic mass stationary relative to thesupport, the seismic mass being moved laterally of the direction ofmovement of the operator when subjected to an acceleration pulse ofpredetermined amplitude and time, said lateral movement of the seismicmass causing movement of the seismic mass and the member normally of thesupport by camming action of the balls in the conical Depressions toactivate the first and second mechanical amplifying means and move theoperator linearly to actuated position.